| 摘要 |
PROBLEM TO BE SOLVED: To provide a DC/DC converter that reduces power consumption and can start in a short time.SOLUTION: Voltage Vgenerated at a second output capacitor Co2 is input into a power terminal VCC. Input voltage Vis input into a high voltage terminal VH. A charging transistor M2 is an N-channel MOSFET (Metal Oxide Semiconductor Field Effect Transistor) disposed between the high voltage terminal VH and the power terminal VCC and biased to be normally on. A current limiting circuit 40 limits charge current Iflowing from the high voltage terminal VH to the power terminal VCC in a first state in which the voltage Vat the power terminal VCC is lower than first predetermined threshold voltage V, and lowers the charge current Isubstantially to zero in a second state in which the voltage Vis higher than second threshold voltage V.SELECTED DRAWING: Figure 3 |
